CN102131335A - Dimming control driver of cold cathode florescent lamp and dimming control method - Google Patents
Dimming control driver of cold cathode florescent lamp and dimming control method Download PDFInfo
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- CN102131335A CN102131335A CN2010100024027A CN201010002402A CN102131335A CN 102131335 A CN102131335 A CN 102131335A CN 2010100024027 A CN2010100024027 A CN 2010100024027A CN 201010002402 A CN201010002402 A CN 201010002402A CN 102131335 A CN102131335 A CN 102131335A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
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Abstract
The invention discloses a driver of a cold cathode florescent lamp. The driver can dim a lamp module according to a control signal generated by a waveform generator used for dimming control. The waveform generator is used for generating the control signal and inputting the control signal into the driver of the cold cathode florescent lamp. The waveform generator comprises a square wave generating unit, a direct-current voltage-generating unit and an output unit. The square wave generating unit is used for generating a square wave having a first level and a second level. The direct-current voltage-generating unit is used for generating a direct-current voltage having a third level. The output unit is used for outputting the control signal according to a switching signal. The control signal is the square wave in a first time period of a cycle time and is the direct-current voltage in a second time period of the cycle time.
Description
Technical field
The present invention system is relevant to a kind of driver of cathode fluorescent tube, refers to that especially a kind of control signal that waveform generator produced of the brightness adjustment control according to cathode fluorescent tube is carried out the driver of Characteristic for Dimming CCFL pipe and the method for brightness adjustment control.
Background technology
Please refer to the 1st figure, the 1st figure is habitual cathode fluorescent tube (Cold Cathode FlorescentLamp, the schematic diagram of drive circuit 100 CCFL).The driver 100 of cathode fluorescent tube comprises integrated circuit (IC) driver 101, first switch 111, second switch 112, the 3rd switch 113, resistance 121, electric capacity 122, resistance 123, diode 124, electric capacity 125, DC-isolation electric capacity 131, inductance 132 and fluorescent tube module 141.First switch 111 and second switch 112 are controlled by the HG end and the LG end of IC driver 101 respectively, first switch 111 and second switch 112 conducting complementally with close, and under required frequency of operation, respectively have work period (duty cycle) of about 50%.The VCC end of IC driver 101 is used for receiving a supply voltage VCC.The BOOT of IC driver 101 end is used for input voltage source, and diode 124 and electric capacity 125 form bootstrap (bootstrap) circuit so that reference voltage to be provided, and the VS end of IC driver 101 is used for input reference voltage.
The electric capacity 122 that is electrically connected at the resistance 121 of RT end and is electrically connected at the CT end is equal to a RC circuit.IC driver 101 can be controlled the running of first switch 111 and second switch 112 according to the time parameter that resistance 121 and electric capacity 122 are produced, and drives fluorescent tube module 141 to produce drive signal.For instance, the magnitude of voltage that makes the CT end when electric capacity 122 charging greater than the magnitude of voltage of supply voltage VCC 2/3rds the time, IC driver 101 is opened first switches 111 and is also closed second switch 112; The magnitude of voltage that makes the CT end when electric capacity 122 discharge is less than three/for the moment of the magnitude of voltage of supply voltage VCC, and IC driver 101 is closed first switch 111 and opened second switch 112.Therefore, can adjust by resistance 121 and electric capacity 122 cycle time of drive signal.In addition, IC driver 101 can be closed fluorescent tube module 141 (shut down) according to the magnitude of voltage of CT end, when the magnitude of voltage of CT end during less than the sixth of the magnitude of voltage of supply voltage VCC, IC driver 101 is closed first switch 111 and second switch 112, to close fluorescent tube module 141.For example, the 3rd switch 113 be electrically connected at CT end and ground end between, when the 3rd switch 113 was switched signal SD and opens, the magnitude of voltage of CT end will be pulled to the ground terminal voltage made IC driver 101 close fluorescent tube module 141.Therefore, the CT end by IC driver 101 can carry out brightness adjustment control to fluorescent tube module 141.
Summary of the invention
The present invention system provides a kind of driver of cathode fluorescent tube of tunable optical control.This driver comprises two outputs and a duration of oscillation input.This two output is used for driving a fluorescent tube module.This duration of oscillation input is used for receiving a control signal, so that this fluorescent tube module is carried out brightness adjustment control.This control signal is the square wave with one first level and one second level in one first period of time one-period, and this control signal is one the 3rd level in one second period of this cycle time.
The present invention provides a kind of waveform generator of brightness adjustment control of cathode fluorescent tube in addition.The waveform generator of the brightness adjustment control of this cathode fluorescent tube comprises a square wave generation unit, a direct current voltage generation unit and an output unit.This square wave generation unit is used for producing the square wave with one first level and one second level.This direct voltage generation unit is used for producing the direct current voltage with one the 3rd level.This output unit is used for switching signal according to one and exports this square wave and one second period that should cycle time is exported this direct voltage in one first period of time one-period.
The present invention provides a kind of method of brightness adjustment control of cathode fluorescent tube in addition.This method comprises to be switched signal according to one and produces a control signal, and this control signal is the square wave with one first level and one second level in one first period of time one-period, and this control signal is one the 3rd level in one second period of this cycle time; And one fluorescent tube module is carried out brightness adjustment control according to this control signal.
Description of drawings
The 1st figure is the schematic diagram of the driver of habitual cathode fluorescent tube.
The 2nd figure is the schematic diagram of the driver of cathode fluorescent tube of the present invention.
The 3rd figure is the oscillogram of control signal of the present invention.
The 4th figure is the schematic diagram of the control signal of three kinds of different brightness.
Wherein, description of reference numerals is as follows: wherein, description of reference numerals is as follows:
100, the driver of 200 cathode fluorescent tubes
101,201 driver ics
111 first switches
112 second switches
113 the 3rd switches
121,123 resistance
122,125 electric capacity
124 diodes
131 DC-isolation electric capacity
132 transformers
141 fluorescent tube modules
250 waveform generators
251 square wave generation units
252 direct voltage generation units
253 output units
DIM, DIMa, DIMb, DIMc control signal
The SD switching signal
The VCC supply voltage
V1 first level
V2 second level
V3 the 3rd level
The W square wave
The D direct voltage
T cycle time
First period of t1
Second period of t2
Embodiment
Please refer to the 2nd figure, the 2nd figure is cathode fluorescent tube of the present invention (Cold Cathode FlorescentLamp, the schematic diagram of driver 200 CCFL).The driver 200 of cathode fluorescent tube comprises integrated circuit (IC) driver 201 and waveform generator 250, and wherein the framework of IC driver 201 and operation principles are similar in appearance to habitual IC driver 101.Waveform generator 250 is electrically connected at the CT end of IC driver 201, is used for producing control signal S.IC driver 201 can produce the drive signal of fluorescent tube module 141 or fluorescent tube module 141 be closed (shut down) according to the magnitude of voltage of CT end.For instance, when the magnitude of voltage of CT end during greater than first threshold, IC driver 201 is opened first switches 111 and is also closed second switch 112; When the magnitude of voltage of CT end during less than second threshold value, IC driver 201 is closed first switch 111 and is opened second switch 112; When the magnitude of voltage of CT end during less than the 3rd threshold value, IC driver 201 is closed first switch 111 and second switch 112; In the present embodiment, first threshold is that 2/3rds, second threshold value of the magnitude of voltage of supply voltage VCC is that the 1/3rd, the 3rd threshold value of the magnitude of voltage of supply voltage VCC is the sixth of the magnitude of voltage of supply voltage VCC.Therefore, the magnitude of voltage that waveform generator 250 is held according to CT produces the control signal DIM with first level, second level and the 3rd level and is input to the CT end, to replace the circuit that is electrically connected at RT end and CT end in the habitual circuit by resistance, electric capacity and switch, wherein first level is greater than first threshold, second level is less than second threshold value, and the 3rd level is less than the 3rd threshold value.So, IC driver 201 carries out brightness adjustment control according to the received control signal DIM of CT end to fluorescent tube module 141.
Please also refer to the 2nd figure and the 3rd figure, the 3rd figure is the oscillogram of control signal DIM of the present invention.Waveform generator 250 produces control signal DIM according to switching signal SD, so that fluorescent tube module 141 is carried out brilliance control.Waveform generator 250 comprises square wave generation unit 251, direct voltage generation unit 252 and output unit 253.Square wave generation unit 251 is used for producing the square wave W with the first level V1 and second level V2.Direct voltage generation unit 252 is used for producing the direct voltage D with the 3rd level V3.The magnitude of voltage of the first level V1, the second level V2 and the 3rd level V3 can be done suitable variation according to user's demand.In present embodiment and since when the magnitude of voltage of CT end greater than the magnitude of voltage of supply voltage VCC 2/3rds the time, IC driver 201 unlatchings first switches 111 also cut out second switch 112; When the magnitude of voltage of CT end less than 1/3rd of the magnitude of voltage of supply voltage VCC, IC driver 201 is closed first switch 111 and is opened second switch 112; When the magnitude of voltage of CT end during less than the sixth of the magnitude of voltage of supply voltage VCC, IC driver 201 is closed first switch 111 and second switch 112, therefore, the first level V1 is greater than 2/3rds of the magnitude of voltage of supply voltage VCC, the second level V2 is less than the 1/3rd, the 3rd level V3 of the magnitude of voltage of the supply voltage VCC sixth less than the magnitude of voltage of supply voltage VCC.Output unit 253 according to switching signal SD output square wave W and direct voltage D to produce control signal DIM.More particularly, output unit 253 is at the first period t1 output square wave W and the second period t2 output dc voltage D of one-period time T.
When control signal DIM is when having the square wave W of the first level V1 and the second level V2, IC driver 201 drives fluorescent tube modules 141, the first switches 111 and will open and close along with the frequency complementary ground of square wave W with second switch 112.When control signal DIM is that IC driver 201 is closed fluorescent tube module 141 when having the direct voltage D of the 3rd level V3.Shown in the 3rd figure, control signal DIM is the square wave W with the first level V1 and second level V2 at the first period t1 of T cycle time, and control signal DIM cycle time T the second period t2 be the direct voltage D of the 3rd level; That is IC driver 201 fluorescent tube driver module 141 in the first period t1 of T cycle time, and in the second period t2 of T cycle time, fluorescent tube module 141 is closed.In the present embodiment, T cycle time of control signal DIM is 5ms (that is the frequency of control signal DIM is 200Hz), and the frequency of square wave W is 50kHz.In addition, in the cycle time of control signal DIM T, the time that the square wave W of control signal DIM is continued (the first period t1) has determined the brightness that fluorescent tube module 141 is produced with the time (the second period t2) that direct voltage D is continued, and the length of the first period t1 and the second period t2 is determined by switching signal SD.Therefore, the control signal DIM that produces by waveform generator 250 can reach the purpose of fluorescent tube module 141 light modulations.
Please refer to the 4th figure, the 4th figure is the schematic diagram of the control signal of three kinds of different brightness.CCFL driver 200 can drive fluorescent tube module 141 according to control signal DIMa, DIMb, DIMc respectively, and makes fluorescent tube module 141 produce three kinds of different brightness.In control signal DIMa, DIMb, DIMc, the first period t1 is the time that square wave W is continued, and the second period t2 is the time that direct voltage D is continued.When the first period t1 of control signal DIMa and the ratio of the second period t2 are 1: 3, fluorescent tube module 141 can produce the light of first brightness value.Since fluorescent tube module 141 at the first period t1 for opening, and at the second period t2 for closing, that is fluorescent tube module 141 time of closing three times during for unlatching are so the light of first brightness value is about complete 25% when bright of fluorescent tube module 141.When the ratio of the first period t1 of control signal DIMb and the second period t2 was 1: 1, fluorescent tube module 141 can produce the light of second brightness value.Because fluorescent tube module 141 time of closing is equal to the time that fluorescent tube module 141 is opened, so the light of second brightness value is about complete 50% when bright of fluorescent tube module 141.When the ratio of the first period t1 of control signal DIMc and the second period t2 was 3: 1, fluorescent tube module 141 can produce the light of the 3rd brightness value.Because the time that fluorescent tube module 141 is opened is three times when closing, so the light of the 3rd brightness value is about complete 75% when bright of fluorescent tube module 141.Therefore, can make fluorescent tube module 141 produce the light of different brightness values by the first period t1 that adjusts control signal DIM with the ratio of the second period t2.
In sum, the invention provides the driver of a cathode fluorescent tube and the waveform generator of a brightness adjustment control.The driver of this cathode fluorescent tube comprises two outputs and a duration of oscillation input, and wherein two outputs are used for driving a fluorescent tube module.The waveform generator of this brightness adjustment control is used for producing a control signal and imports this duration of oscillation input.The waveform generator of this brightness adjustment control comprises a square wave generation unit, a direct current voltage generation unit and an output unit.This square wave generation unit is used for producing the square wave with one first level and one second level.This direct voltage generation unit is used for producing the direct current voltage with one the 3rd level.This output unit is used for switching signal according to one and exports this control signal, and this control signal is this square wave in one first period of time one-period, and is this direct voltage in one second period of this cycle time.When this control signal is this square wave, this fluorescent tube module of the driver drives of this cathode fluorescent tube; When this control signal was this direct voltage, the driver of this cathode fluorescent tube was closed this fluorescent tube module, to reach the purpose to this fluorescent tube module light modulation.
The above only is the preferred embodiments of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.
Claims (16)
1. the driver of the cathode fluorescent tube of a tunable optical control is characterized in that, comprises:
Two outputs are used for driving a fluorescent tube module; And
One duration of oscillation input is used for receiving a control signal, so that this fluorescent tube module is carried out brightness adjustment control, this control signal one first period of time one-period for have one first level with
One square wave of one second level, this control signal in one second period of this cycle time is
One the 3rd level.
2. the driver of cathode fluorescent tube as claimed in claim 1 is characterized in that, other comprises:
One power end is used for receiving a supply voltage.
3. the driver of cathode fluorescent tube as claimed in claim 2, it is characterized in that, wherein this first level is greater than 2/3rds of the magnitude of voltage of this supply voltage, this second level is less than the 1/3rd, the 3rd level of the magnitude of voltage of this supply voltage sixth less than the magnitude of voltage of this supply voltage.
4. the driver of cathode fluorescent tube as claimed in claim 1 is characterized in that, wherein when the ratio of this first period and this second period was 1: 3, this fluorescent tube module produced the light of one first brightness value; When the ratio of this first period and this second period was 1: 1, this fluorescent tube module produced the light of one second brightness value; And when the ratio of this first period and this second period was 3: 1, this fluorescent tube module produced the light of one the 3rd brightness value.
5. the driver of cathode fluorescent tube as claimed in claim 4 is characterized in that, wherein the 3rd brightness value is greater than this second brightness value, and this second brightness value is greater than this first brightness value.
6. the driver of cathode fluorescent tube as claimed in claim 1 is characterized in that, wherein this first period and this second period are the continuous period.
7. the waveform generator of the brightness adjustment control of a cathode fluorescent tube is characterized in that, comprises:
One square wave generation unit is used for producing the square wave with one first level and one second level;
One direct current voltage generation unit is used for producing the direct current voltage with one the 3rd level; And
One output unit is used for switching signal according to one and exports this square wave and one second period that should cycle time is exported this direct voltage in one first period of time one-period.
8. the waveform generator of the brightness adjustment control of cathode fluorescent tube as claimed in claim 7, it is characterized in that, wherein this first level is greater than 2/3rds of the magnitude of voltage of a supply voltage, this second level is less than the 1/3rd, the 3rd level of the magnitude of voltage of this supply voltage sixth less than the magnitude of voltage of this supply voltage.
9. the waveform generator of the brightness adjustment control of cathode fluorescent tube as claimed in claim 7 is characterized in that, wherein when the ratio of this first period and this second period is 1: 3, can drive the light that a fluorescent tube module produces one first brightness value; When the ratio of this first period and this second period is 1: 1, can drive the light that this fluorescent tube module produces one second brightness value; And when the ratio of this first period and this second period is 3: 1, can drive the light that this fluorescent tube module produces one the 3rd brightness value.
10. the waveform generator of the brightness adjustment control of cathode fluorescent tube as claimed in claim 7 is characterized in that, wherein the 3rd brightness value is greater than this second brightness value, and this second brightness value is greater than this first brightness value.
11. the waveform generator of the brightness adjustment control of cathode fluorescent tube as claimed in claim 7 is characterized in that, wherein this first period and this second period are the continuous period.
12. the method for the brightness adjustment control of a cathode fluorescent tube is characterized in that, comprises:
Switch signal according to one and produce a control signal, this control signal is the square wave with one first level and one second level in one first period of time one-period, and this control signal is one the 3rd level in one second period of this cycle time; And
According to this control signal one fluorescent tube module is carried out brightness adjustment control.
13. method as claimed in claim 12 is characterized in that, wherein according to this control signal this fluorescent tube module is carried out brightness adjustment control and comprises:
When the ratio of this first period and this second period was 1: 3, this fluorescent tube module produced the light of one first brightness value;
When the ratio of this first period and this second period was 1: 1, this fluorescent tube module produced the light of one second brightness value; And
When the ratio of this first period and this second period was 3: 1, this fluorescent tube module produced the light of one the 3rd brightness value.
14. method as claimed in claim 13 is characterized in that, wherein the 3rd brightness value is greater than this second brightness value, and this second brightness value is greater than this first brightness value.
15. method as claimed in claim 12, it is characterized in that, wherein this first level is greater than 2/3rds of the magnitude of voltage of a supply voltage, and this second level is less than the 1/3rd, the 3rd level of the magnitude of voltage of this supply voltage sixth less than the magnitude of voltage of this supply voltage.
16. method as claimed in claim 12 is characterized in that, wherein this first period and this second period are the continuous period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010100024027A CN102131335A (en) | 2010-01-20 | 2010-01-20 | Dimming control driver of cold cathode florescent lamp and dimming control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010100024027A CN102131335A (en) | 2010-01-20 | 2010-01-20 | Dimming control driver of cold cathode florescent lamp and dimming control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102131335A true CN102131335A (en) | 2011-07-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010100024027A Pending CN102131335A (en) | 2010-01-20 | 2010-01-20 | Dimming control driver of cold cathode florescent lamp and dimming control method |
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| CN (1) | CN102131335A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1142310A (en) * | 1994-12-05 | 1997-02-05 | 菲利浦电子有限公司 | Circuit arrangement for alternatingly establishing and extinguishing a discharge in each of plurality of discharge paths |
| KR20070077860A (en) * | 2006-01-25 | 2007-07-30 | 엘지이노텍 주식회사 | Dimming circuit of inverter using a display |
| CN101170864A (en) * | 2007-08-03 | 2008-04-30 | 崇贸科技股份有限公司 | Ballast with pre-heating controlled IC |
-
2010
- 2010-01-20 CN CN2010100024027A patent/CN102131335A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1142310A (en) * | 1994-12-05 | 1997-02-05 | 菲利浦电子有限公司 | Circuit arrangement for alternatingly establishing and extinguishing a discharge in each of plurality of discharge paths |
| KR20070077860A (en) * | 2006-01-25 | 2007-07-30 | 엘지이노텍 주식회사 | Dimming circuit of inverter using a display |
| CN101170864A (en) * | 2007-08-03 | 2008-04-30 | 崇贸科技股份有限公司 | Ballast with pre-heating controlled IC |
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Application publication date: 20110720 |